Teslas and Amps/meter are two completely different types of units, so you can't convert between them. See below for a little more explanation on that. However, to calculate B from H, or vice-versa, you can use the equation B = H * mu, where mu is the permeability of the material you're looking at. The permeability is basically a measure of how well certain materials transmit magnetic fields. For example, for Bismuth, mu is 1.2564 * 10^-6 N/A² (Newton's per ampere squared). Unfortunately this tangles up the units a bit more.